Identify the proximal segments of the cranial nerves emerging from the base of the skull.

1. Identify the stylohyoid, styloglossus and stylopharyngeus muscles attaching to the styloid process. (G 8.28;N 70;Gl 44.28)
2. Identify and trace the facial nerve to the stylomastoid foramen. (G 7.47C;N 71;Gl 40.24) The stylomastoid foramen is typically in the same plane as the posterior border of the external auditory meatus.
3. Identify and trace the accessory nerve in the superior direction until it approaches the jugular foramen. (G 7.47C;N 32;Gl 44.30)
4. Identify and trace the hypoglossal nerve (superficial to the internal and external carotid arteries) in the superior direction until it appears to become a branch of the vagus nerve. (G 7.47C;N 71;Gl 44.30)
   Important Relationship

   • The hypoglossal nerve passes lateral to the internal and external carotid arteries, and medial to the internal jugular vein.
5. Identify and trace the superior laryngeal nerve (deep to the external and internal carotid arteries) in the superior direction until it branches from the vagus nerve.
Important Relationship
• The superior laryngeal nerve passes medial to the internal and external carotid arteries.
6. Attempt to identify and trace the glossopharyngeal nerve and pharyngeal branch (vagus nerve) in the superior direction until they approach the vagus nerve and the jugular foramen.
   Important Relationship

   • The glossopharyngeal nerve (and pharyngeal branch of the vagus nerve) passes between the internal and external carotid arteries.